1 Ecology relating to or characteristic of the climatic zone south of the Arctic, especially the cold temperate region dominated by taiga and forests of birch, poplar, and conifers:northern boreal forest
(Boreal) Botany relating to or denoting a phytogeographical kingdom comprising the arctic and temperate regions of Eurasia and North America.
2 (Boreal) Geology relating to or denoting the second climatic stage of the postglacial period in northern Europe, between the Preboreal and Atlantic stages (about 9,000 to 7,500 years ago), marked by a warm, dry climate.